1. Technical Field
The present invention relates generally to a system for carrying out a medical procedure, and more specifically, to a system for carrying out a diagnostic or therapeutic procedure that utilizes two or more wire guides having different properties.
2. Background Information
In modern medicine, vascular procedures are frequently carried out by introducing a wire guide into a vessel, and directing the wire guide through the vessel to a target area for the procedure. Such wire guides are typically introduced into the vessel by well-known procedures, such as the Seldinger percutaneous access technique. The wire guide to be introduced will ideally have a suitable combination of flexibility and stiffness that allows it to be directed to the area of interest.
Introducing a wire guide in this manner can be relatively straightforward if the target area is situated in a portion of the vasculature that is not difficult to reach. However, it is often necessary to traverse tortuous areas of the vessel, and/or to cross one or more lesions in the vessel in order to reach the target area. In such cases, directing the wire guide to the target area can be a very time consuming and painstaking procedure, if it can be accomplished at all. Generally, the wire guide to be inserted is fairly “floppy”, or flexible, in order to optimize the chances for successful positioning.
Although such wire guides are beneficial for purposes of traversing the tortuous areas of the vasculature, a highly flexible wire guide will often not be well suited for carrying out successive steps in the medical procedure. For example, in some diagnostic and interventional procedures, such as angioplasty and various stenting operations, a catheter is introduced over the wire guide and directed toward the area of interest. However, highly flexible wire guides often do not have sufficient stiffness to allow the catheter to track the wire guide through the vessel. As a result, the catheter may disturb or displace the distal tip of the wire guide away from the area of interest. This results in the need to exchange the first wire guide for a second, stiffer, wire that has sufficient strength to control the catheter.
The conventional approach to this wire exchange involves advancing the catheter as far as possible along the first wire, withdrawing the first wire, and advancing a second, stiffer, wire in its place through the vessel. However, this process results in the loss of the original wire placement. As a result, the physician must re-access the area of interest with a stiffer wire that is more difficult to advance into the tortuosity and/or lesion area. This process is time consuming, if possible at all, and exposes the patient to increased risk of failure.
Accordingly, there exists a need for a system and method that will allow for placement of a catheter and related devices in a vessel over a second wire guide, in a manner that does not sacrifice the original access and/or placement achieved by the first wire guide.